Answer
Energy as heat absorbed $=57.2597\text{ kJ}$
Work Step by Step
Moles of $CO_2=mass/molarmass$
Moles of $CO_2=100/44.01=2.272\text{ moles}$
from the question we are told that for every 1 mol of $CO_2$ that sublimes $25.2\text{ kJ}$ of heat is absorbed
then, how much heat will $2.272$ mol of $CO_2$ absorb
$(2.272\text{ mol } CO_2\times25.2\text{ kJ})/(1\text{ mol } CO_2)=57.2597\text{ kJ}$
